Zero Grazing machine test – Part 2

This week, we conclude our report on zero-grazing machines, with our test of the Zero Grazer ZG75 and the Belmac O Grazer 800. These are both Irish-made machines, showcasing local knowledge and engineering skills.

Zero Grazer, a company run by Niall O’Reilly, is one the most established in the field. Niall offers an on-farm grass management advice package, in addition to selling the machines. His experience is that zero-grazing can take place at a time of year when ground conditions will not be good enough for a cow to walk on but when there is a cover of grass worth cutting.

Often, at this time of the year, farmers can harvest a grass crop from early paddocks to clean the sward. This allows the cows to have access to fresh grass and ensures that the re-growth is a fresh aftergrass as soon as the cows go out weeks later.

The best advice when looking at the zero-grazing system is to buy a machine to suit your farm conditions. Aim for grass dry matter utilisation.

Machines should be selected to suit the herd size, distance from the grass fields, farm fragmentation and whether the zero-grazing will be seasonal or full time. You also need to consider machine weight and capacity and existing farm tractor and labour resources.

There is little advantage in choosing a machine that allows you to bring a big load, but does significant damage to the fields because of its weight.

The footprint of the zero-grazing machine should be such that it does minimal field damage and allows for fast grass re-growth.

Zero-grazing could also be a useful additional enterprise for smaller contractors. This option will give additional work at a time of the year when tractors are idle.

Zero-grazing will demand time on the farm. That time can be scarcer depending on the time of the year.

For spring-calving dairy farmers, zero grazing may be difficult in terms of time available as they are busy with calving.

For autumn zero-grazing on such farms, the system is a lot easier, as more time will be available. For autumn-calving herds, the opposite is the case.

This emphasises the need to look at your system carefully first, take some time to examine what you need, make a list of your priorities by writing them down before you go out shopping for a machine.

You can then finalise your machine choices against the measurable needs of the farm. And you are more likely to get the results you want.

The Zero Grazer range is probably the longest established on the market. The first machines were imported from Italy by Niall O’Reilly of Zero Grazer and, since then, some models have been designed and manufactured by Hand Enginerring, Oldcastle, Co Meath.

The Zero Grazer ZG75 is one of the Irish-manufactured machines in the range. It is one of four models. Niall also supplies the smaller AB range in five models from the AB40 to the AB80. At the larger end of the scale, he supplies the ZG90 and ZG100. All of the ZG-coded machines are built in Ireland. Niall offers a total of 11 models to choose from.

Specification

The Zero Grazer ZG75 is a bogie-type, twin-axle machine with a capacity of 36m3, which Niall O’Reilly claims is enough to feed about 130 cows. The machine is well-built in terms of structure and design. It is also the lightest of the test group at almost 4t, which makes it suitable for Irish conditions.

The drawbar of the ZG75 is a telescopic double box frame unit. This is hydraulically controlled from the tractor cab to bring the machine in and out when moving from transport to working position in the field. There is a mechanical lock for road work.

The main drawbar is a strong, drop-type unit. It can be towed by a pick-up hitch, a clevis-type drawbar, which we had, or a higher continental-type hitch. The frame at the front of the machine is designed to take a heavy load and doubled box sections at each side near the mower-carrying frame.

The Zero Grazer machine is fitted with a 2.1m (7ft), two-drum Galfre mower, similar to that fitted to two of the other machines. What is different about the mower is the way that it is mounted to the body of the machine.

The mower unit is carried on a spring suspension system which is pivoted from the rear. The tension adjustment on the springs will dictate the way that the machine follows the ground and also the height of cut. It is easy to adjust for cutting height and it has good height clearance when on the road.

The mower section is lifted out of work by two hydraulic rams, one on each side. Lifting the mower automatically shuts off power to the drum mower. There are plastic stops to set the transport and mowing height.

The drive to the mower is by means of a wide-angled PTO shaft and drive belts. That driveline continues down the side of the machine to power the elevator unit.

Once the grass is cut by the drum mowers, it is transferred into the trailer body of the machine by means of a 1,250mm-wide elevator unit. This is an eight-bar unit. The grass is then moved to the rear of the machine by means of a hydraulic-driven 14t rated four-chain and slat moving floor.

The floor is driven by a reduction gearbox to the rear of the machine. This keeps an even flow of grass to the rear. The rear-door design is novel and, when locked, it is held in place by a mechanical locking system. When you engage the door to open, it is first raised on hydraulic rams to clear the mechanical holders and then opens wide.

The machine was fitted with a convenient central lubrication system. It was also fitted with a camera on the rear. The lighting kit is road friendly and includes durable LED units.

The Zero Grazer ZG75 runs on four 500/50-17 flotation tyres, which may vary in make, depending on supplies. Axle width across the tandem bogie unit is reasonably wide. Braking is standard all round.

Two double-acting hydraulic services are used to operate all hydraulic functions, including the drawbar ram, mower hydraulic ram and floor mechanism.

The machine is controlled by means of an electro-hydraulic diverter unit in the tractor cab.

Operation

We joined Niall O’Reilly in the cab of the Tumosan 8105 Turbo tractor that we had on loan from Tumosan Ireland to drive the Zero Grazer ZG75.

The tractor’s four-cylinder turbo-charged engine power was more than adequate for the machine in a field that was relatively smooth and even.

Before starting to work, the hydraulic ram on the drawbar was powered out which fully offset the machine, making it ready to mow and collect fresh grass. To start up, the mowing unit was lowered to the ground and then the tractor’s PTO was engaged to run the mower.

The start-up was relatively smooth and Niall recommended slightly lower revs on the PTO than the usual 540rpm figure.

You will notice the power demand when you engage the PTO, but it was not significant. With the PTO engaged, the loading elevator comes into action. Niall drove clockwise around the plot of grass, closing in the drawbar to a narrower position for tighter corners.

Then he left us at it. Driving the machine was easy apart from judging when the floor needs to push grass to the rear. Moving the drawbar in and out at corners was easy but you need to make sure that you don’t tighten it fully and engage the mechanical lock that’s needed for road work.

Even though there is a punched metal front to the machine, it is relatively easy to see when the grass has built up and it’s time to engage the floor chain to move it back. This is easily done by means of the spool valves which are split on the electronic control box with the floor and mower section on one switch, while the door and the drawbar are on the other.

In the field, the drawbar and floor movements are used as the mower section is on a constant float position. The machine, even when full, did not put undue weight on the tractor; it was well within its capacity driving at close to 8km to 9km/hr.

The position of the bogie tandem axle made for an easily balanced machine, with minimal weight resting on the mower section. This is important in terms of wear on the base of the mower drums.

The machine was compact when it came to getting in and out of the field. On the road, the drawbar design made it a stable machine as we faced some deep potholes. There is good mower clearance for bad gaps. The machine is easy to unload by engaging the door-opening section and keeping the hydraulic power to the unloading floor. It is relatively compact for yard manoeuvring.

Niall O’Reilly has more experience than most of the practical aspects of operating the Zero Grazer machine. He also provides farm advice on managing the system to best effect, along with a grass seed supply business. Niall does not sell any other type of equipment.

The Belmac O-Grazer 800 was the machine we had on test from Belmac Engineering Ltd, Clonboniff, Belmont, Birr, Co Offaly. Belmac Engineering was set up Michael Gavin in 1987. The company manufactures a range of agricultural machinery including toppers, side spreaders, slurry tankers, agitators, post drivers, swath wilters and diet feeders. Belmac manufactured its first zero-grazing machines three years ago.

Specification The Belmac O-Grazer 800 is a twin-axle, zero-grazing machine with a rated load capacity of 6.5t of fresh grass. The machine has a minimum recommended power requirement of 110hp. The O-Grazer has its own independent hydraulic system with an oil tank capacity of 20 litres.

The drive line on the machine goes through two wide-angle PTOs from tractor to drawbar and from drawbar to mower drive. The on-board hydraulic pump takes its drive off this PTO shaft.

The grass is cut with a 2.1m-wide Galfre two-drum mower, as standard. The cutting height is adjustable from its hinge point behind the mower.

The elevator box is spring-loaded and it is hydraulically driven from the machine’s own hydraulic system. Belmac claims that heavy duty bearings are used throughout the machine.

Once the grass is loaded into the wagon, it is moved rearwards by two pairs of chains driving a series of floor slats. The chains have a rated load capacity of 14t.

The Belmac O-Grazer 800 is fitted with LED lights as standard. The machine is painted with Tuff 2-Pac paint for better protection.

There are no cables from the tractor to the zero-grazing machine and that is because the operation of the Belmac O-Grazer is cleverly controlled by a handheld remote control unit. This sends a radio signal to the hydraulic control unit to operate the elevator and floor-moving chain. It was the only machine at the test that used this system.

The remote control unit operated the chain and slat floor (on and off), the grass elevator (on and off) and opening and closing of the hydraulic back door. The O-Grazer uses the tractor’s hydraulics to move the drawbar in and out and, also, to lift the mower.

The Belmac O-Grazer 800 comes on 500 tyres as standard and ADR bogie axles.

Operation

Ronan Feighery, of Belmac Engineering and Macra, was co-piloting Belmac O-Grazer 800 for the test day.

Ronan has worked on the product development and sales of the O-Grazer at Belmac. He runs a Belmac O-Grazer on his own farm in Co Offaly, so he has plenty of experience operating these machines.

For the Irish Farmers Journal test, we powered the Belmac O-Grazer with a Case IH Farmall 105 U Pro supplied by JH Fitzpatrick of Monasterevin. This is a compact four-cylinder tractor which would be of the engine power size commonly found pulling zero-grazing machines on Irish farms.

In the field, the tractor’s hydraulics power out the drawbar and the mower is lowered before the PTO is turned on. Once the PTO is engaged, the O-Grazer’s own hydraulic come to life. The elevator is then switched from the handheld remote control unit. The machine can now be driven forward at a speed depending on tractor power, volume of the grass crop and the ground conditions.

Once filled and out on the road and despite a lack of suspension, the O-Grazer travelled well but was a bit giddy due to the single drawbar design. Unloading the machine was not a problem. Some of the roads we travelled on were very narrow and despite this, manoeuvrability either into or out of fields was relatively easy.

The wheels are positioned roughly midway along the length of the machine, which is a feature of these types of machines that does create some a tail-swing. We anticipated the tail-swing and didn’t hit anything on test day.

Overall, it was an easy machine to get used to operating. The remote control system is easy to use after five or six loads and has the advantage that you can operate the floor when outside of the tractor cab, to keep an eye on the system from beside it. The tractor was well-matched to the size of the O-Grazer; it had good traction in the field and was compact in tight yards.

In this Irish Farmers Journal zero-grazing machine test, we learned much about the design and operation of zero-grazing machines, which hopefully has been conveyed to you, our readers. Here is a list of some of what we picked up in terms of knowledge rather than grass:

We looked at the machines under a number of headings to evaluate them for farm use. The headings included: value for money, build quality, ease of use and serviceability.

All of these areas were assessed following a detailed description of the machines provided by the suppliers. This assessment was further measured by the in-field driving experiences of our team of testers.

Each of these four areas was given a ‘1 to 5’ score (Table 2, page 54/55). While we came up with a result which rated the Irish-built Zero Grazer ZG75 as the best machine on the day, it is important that all machines are assessed on their suitability for the farm, field conditions and the operator’s skill, as well as matching the farm’s tractor resources before deciding.

Machine test participants The group who took part in the Irish Farmers Journal zero-grazing machine tests are pictured above: Liam Ryan, owner of the Condell machine; Niall O’Reilly of Zero Grazer; Bruce Lett, machinery reporter; Nigel and Desmond Condell, of Desmond Condell Engineering; Justin Cleary of Barnaboy Enterprises; Wray Platt, farm manager at Gurteen College and David Kincaid, Irish Farmers Journal. We would like to thank all of the zero-grazing machine suppliers who took part in our group test for their support and co-operation. We would also like to thank our tractor suppliers, including Case IH, New Holland through Gurteen College and Tumosan Tractors Ireland. Our thanks also to Mike Pearson, Gurteen College principal, and Wray Platt, farm manager and his team, as well as local farmer Patrick Cahalane from Ballingarry, Roscrea, who provided us with the weighbridge facilities.

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